Keogh的SAX聚集近似算法，首先采用PAA分段，然后正态化序列，在对应表上查询符号表示，这是一个很经典的时间序列表示方法-Keogh' s SAX gathered approximation algorithm, the first use PAA segment, then normal sequence, query on the corresponding symbol table indicates, this is a classic representation of the time series